CN106876261A - A kind of flexible conductive wire, and its preparation method and application - Google Patents

Abstract

The present invention relates to a kind of preparation method of flexible conductive wire, comprise the steps：S11：Microballoon dispersion liquid is prepared, microballoon is added in solvent, be uniformly dispersed and obtain microballoon dispersion liquid；S12：Microsphere template array is prepared, by microballoon dispersion on substrate, removal solvent is dried, microsphere template array is obtained；S13：Deposited metal line, to deposited metal layer on microsphere template, the metal level filled in the gap between the microsphere surface and microballoon forms the metal film with network structure；S14, formation flexible conductive wire, after removal substrate and microballoon, then the flexible conductive wire that the metal film with network structure is etched into predetermined shape.Resistivity can keep stabilization in the flexible conductive wire BENDING PROCESS that the present invention is provided, and extend the life-span of flexible back plate.

Description

A kind of flexible conductive wire, its preparation method and application

technical field

The invention relates to the field of flexible display devices, in particular to a flexible conductive wire suitable for flexible display devices and a preparation method thereof, as well as a flexible backplane provided with such flexible conductivity and a preparation method thereof.

Background technique

With the continuous development of display technology, OLED (Organic Light Emitting Diode) has increasingly become an international research hotspot due to its advantages of high luminance, rich colors, low-voltage DC drive, and simple preparation process. OLED has a wider field of view and can be made into larger-sized products to meet users' requirements for different sizes. The above-mentioned outstanding advantages determine that OLED will become the mainstream of next-generation display technology. With the development of material technology, display screens can already be made into bendable forms. Devices with flexible displays have many advantages, such as being portable, bendable, and deformable at will. However, the resistance of the metal wires inside the flexible backplane tends to change greatly or even break when it is bent, which affects the life of the screen.

In order to solve the problem of broken wires, CN203025453U discloses an array substrate and a display device as shown in FIG. 1 , where the metal layer 1 is set in a zigzag shape at the intersection of metal lines to prevent the metal layer 2 from breaking when climbing a slope. This patent only solves the fracture problem when the metal wire climbs a slope, but the metal wire still has the fracture problem when it is bent repeatedly.

Contents of the invention

Therefore, the technical problem to be solved by the present invention lies in the problem that in the prior art, the metal wire inside the flexible backplane tends to change greatly in resistance or even break when it is bent, and to provide a flexible conductive wire. The resistivity of the flexible conductive wire can be kept stable during the bending process, which prolongs the life of the flexible backplane.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A method for preparing a flexible conductive wire, comprising the steps of:

S11: Preparation of microsphere dispersion

Add the microspheres into the solvent and disperse evenly to obtain a microsphere dispersion;

S12: Preparation of microsphere template array

coating the microsphere dispersion on the substrate, drying and removing the solvent to obtain a microsphere template array;

S13: depositing metal lines

Depositing a metal layer on the microsphere template, the metal layer filled in the surface of the microsphere and the gap between the microspheres forms a metal film with a network structure;

S14, forming a flexible conductive wire

After removing the substrate and the microspheres, the metal film with a network structure is etched into a flexible conductive line of a predetermined shape.

The step S11 is as follows: adding the microspheres into water or an organic solution, adding a surfactant, and then uniformly distributing the microspheres in the solution by ultrasonic vibration to form a microsphere dispersion.

The diameter of the microsphere is 12nm-3um.

The concentration of the microspheres is 0.01-0.15 wt%.

The microspheres are polystyrene microspheres or silicon dioxide microspheres.

The step S14 is: ultrasonically oscillating or high-temperature annealing in the solution, removing the microspheres, and then performing vacuum annealing treatment to obtain a metal film with a network structure, and then etching the metal film with a network structure into a predetermined shape. Flexible conductive wire.

The metal layer in step S3 is one or a combination of copper, aluminum, molybdenum or titanium.

A flexible conductive wire prepared by the method for preparing the flexible conductive wire.

A flexible backplane, comprising a flexible substrate and a bottom-gate TFT formed on the flexible substrate, the TFT comprising a gate layer formed on the flexible substrate, a gate insulating layer, a polysilicon semiconductor layer, an interlayer insulating Layer and source/drain electrode layer, the gate layer and/or source/drain electrode layer is the flexible conductive wire described in any one of claims 1-6.

A method for preparing the flexible backplane, comprising the steps of:

S21, preparing the gate layer

According to the method described in any one of claims 1-6, flexible conductive wires are prepared as gate layer;

S22, preparing gate insulating layer, polysilicon semiconductor layer and interlayer insulating layer

Depositing a gate insulating layer, a polysilicon semiconductor layer and an interlayer insulating layer on the gate layer prepared in step S21, and etching the interlayer insulating layer to form a contact hole to expose the polysilicon semiconductor layer;

S22, preparing source and drain layers

The contact hole formed by etching according to the method step S21 is used to prepare a flexible conductive line as the source and drain.

A flexible backplane comprising a flexible substrate and a top-gate TFT formed on the flexible substrate, the TFT comprising an active layer formed on the flexible substrate, a gate insulating layer, an interlayer insulating layer, a gate Layer and source/drain electrode layer, the gate layer and/or source/drain electrode layer is the flexible conductive wire described in any one of claims 1-6.

A method for preparing the flexible backplane, comprising the steps of:

S31, preparing the active layer and the gate insulating layer

Deposit active layer and gate insulating layer on flexible substrate;

S32, preparing the gate layer

preparing a flexible conductive line on the gate insulating layer as a gate layer according to any one of claims 1-6;

S33. Preparing an interlayer insulating layer

Depositing an interlayer insulating layer on the basis of the step S32, and etching the interlayer insulating layer and the gate insulating layer to form a contact hole to expose the active layer;

S34, preparing source and drain layers

According to the method described above, the contact holes formed by etching in the step S34 are used to prepare flexible conductive lines as source and drain electrodes.

The above technical solution of the present invention has the following advantages compared with the prior art:

The preparation method of the flexible conductive wire provided by the present invention is to make an array of polystyrene (PS) microspheres or silicon dioxide (SiO ₂ ) microspheres, and then deposit a metal layer on the array, then remove the microspheres, leaving A metal film with a network structure is formed, and then the metal film is made into metal lines by etching. When the flexible backplane is bent, the use of mesh metal wires can effectively release the stress released by the metal wires during repeated bending, thereby increasing the life of the metal wires, which will greatly improve the bending performance of the flexible backplane and achieve a high flexible screen body. lifespan.

The present invention can control the density of the array by controlling the concentration of the microspheres, so as to prepare the metal film with the required shape and network structure, and further make the metal film into metal wires by etching.

The present invention provides that when the flexible backplane adopts the above-mentioned flexible conductive wire, when the flexible substrate is bent, the resistance of the conductive wire of the TFT will not increase sharply or break, which increases the reliability of the device.

Description of drawings

Fig. 1 is a schematic diagram of the structure of a conductive wire in the prior art;

Fig. 2 is the schematic diagram of microsphere array template;

Fig. 3 is the schematic diagram that PS polystyrene microsphere array template prepares flexible conductive wire;

Fig. 4 is the schematic diagram that the silicon dioxide microsphere array template prepares flexible conductive wire;

FIG. 5 is a schematic diagram of a bottom-gate TFT structure;

FIG. 6 is a schematic diagram of a structure of a top-gate TFT;

The reference numerals in the figure are represented as: 1-flexible substrate, 2-gate layer, 3-gate insulating layer, 4-polysilicon semiconductor layer, 5-interlayer insulating layer, 6-source-drain layer, 7-with Source layer, 11-metal layer, 12-microsphere, 13-glass substrate.

detailed description

In order to make the purpose, technical solution and advantages of the present invention clearer, the following will further describe in detail the embodiments of the present invention in conjunction with the accompanying drawings.

This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims.

Example 1

The preparation method of the flexible conductive wire in the present embodiment comprises the following steps:

S11: Preparation of microsphere dispersion

Add polystyrene microspheres to organic solvent acetone or directly use deionized water, then add surfactant sodium dodecyl sulfate (sodium dodecyl sulfate, sodium salt, SDS), and then distribute the microspheres evenly in the solution by ultrasonic vibration Form a microsphere dispersion in the microsphere dispersion, the diameter of the microsphere is 10nm-3um, and the concentration of the microsphere in the microsphere dispersion is 0.15wt%;

S12: Preparation of microsphere template array

Coating the microsphere dispersion liquid on the glass substrate 13 to form the microsphere template array shown in FIG. Fabrication of flexible conductive wires by template array is shown in FIG. 3 , and microspheres 12 with different diameters are selected according to the thickness of the metal layer to be fabricated. The selection rule is: the radius of the PS microsphere is greater than the thickness of the metal layer 11, so that it can be guaranteed that metal lines connected together will not be formed during the deposition of the metal layer 11, as shown in Figure 3, formed between the microspheres The metal layer 11 and the metal layer 11 above the microspheres are disconnected, which facilitates the formation of grid-like metal lines after removing the microspheres. Deposit the metal layer of 250nm thickness in the present embodiment, the diameter of the selected PS microsphere is 600nm, the metal layer deposited on the microsphere and the metal layer deposited between the microspheres will not become connected together in the deposition process like this metal wire.

S13: depositing metal lines

Depositing an aluminum metal layer on the microsphere template, the metal layer filled in the surface of the microsphere and the gap between the microspheres forms a metal film with a network structure;

S14, forming a flexible conductive wire

Anneal at high temperature in dichloromethane solution, remove the microspheres, and then perform vacuum annealing treatment to obtain a metal film with a network structure as shown in Figure 4, and then etch the metal film with a network structure into a predetermined shape. conductive thread. When the flexible conductive wire prepared in this embodiment is applied to a flexible substrate, when the flexible substrate is bent, the resistance of the conductive wire of the TFT will not increase sharply or break, which increases the reliability of the device.

Example 2

The preparation method of the flexible conductive wire in the present embodiment comprises the following steps:

S11: Preparation of microsphere dispersion

Add silica microspheres to water or an organic solution, then add surfactant sodium lauryl sulfate, and then distribute the microspheres evenly in the solution by ultrasonic vibration to form a microsphere dispersion. The diameter of the microspheres is 10nm-2um, the concentration of microspheres in the microsphere dispersion is 0.01wt%;

S12: Preparation of microsphere template array

The microsphere dispersion is coated on the glass substrate 13 to form the microsphere template array shown in Figure 2, and the microspheres 12 arranged in an array are distributed on the glass substrate 13, and the solvent is removed by drying to obtain the microsphere template array; Silicon microsphere template arrays are used to prepare flexible conductive wires as shown in Figure 4. Silicon dioxide microspheres with different diameters are selected according to the thickness of the metal layer to be fabricated. The thickness of the metal layer 11, as shown in Fig. 4, the diameter of the silicon dioxide microsphere is 150nm, and the thickness of the metal layer is 250nm.

S13: depositing metal lines

Depositing a copper metal layer on the microsphere template, the metal layer filled in the surface of the microsphere and the gap between the microspheres forms a metal film with a network structure;

S14, forming a flexible conductive wire

Vacuum annealing is performed on the basis of step S13 to obtain a metal film with a network structure as shown in FIG. 4 , and then the metal film with a network structure is etched into a flexible conductive line of a predetermined shape.

As another embodiment, the deposited metal layer may also be a molybdenum or titanium metal layer, or a combination of copper, aluminum, molybdenum or titanium. When the flexible conductive wire prepared in this embodiment is applied to a flexible substrate, when the flexible substrate is bent, the resistance of the conductive wire of the TFT will not increase sharply or break, which increases the reliability of the device.

Application example 1

As shown in Figure 5, a flexible backplane includes a flexible substrate 1 and a bottom-gate TFT formed on the flexible substrate 1, and the TFT includes a gate layer 2 formed on the flexible substrate, a gate insulation Layer 3, polysilicon semiconductor layer 4 and source/drain electrode layer 6, the gate layer 2 and source/drain electrode layer 6 are the flexible conductive lines. As other implementations, the TFT can also be: the gate layer 2 adopts the flexible conductive line structure prepared in Example 1 or Example 2, and the source/drain electrode layer 6 adopts a common existing structure; or the source/drain electrode Layer 6 adopts the flexible conductive wire prepared in embodiment 1 or embodiment 2, and gate layer 2 adopts a common existing structure.

The gate insulating layer 3 is selected from but not limited to a stacked structure layer of one or more materials in silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, and titanium oxide. The silicon oxide layer is preferred in this embodiment; The thickness of gate insulating layer 3 described in the embodiment is As another embodiment of the present invention, the thickness of the gate insulating layer 3 can also be All can realize the object of the present invention, belong to the protection scope of the present invention.

The polysilicon semiconductor layer 4 is easily damaged during the patterning of the source/drain electrode layer 6. Therefore, in this embodiment, the polysilicon semiconductor layer is also provided with a layer covering the polysilicon semiconductor layer 4 away from the substrate. 1 surface and side interlayer insulation layer 5. The interlayer insulating layer is selected from but not limited to silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, and titanium oxide, and the stacked structure layer of one or more materials can achieve the purpose of the present invention and belongs to this invention. protection scope of the invention. In this embodiment, the interlayer insulating layer 5 is preferably an etching barrier layer, and the etching barrier layer is preferably a silicon oxide layer with a thickness of

In a thin film transistor (TFT), the source and drain are usually formed in the same layer using the same material. For this reason, for the convenience of description, the layer where the source and the drain are located is generally referred to as source/drain Layer 6. The source/drain layer 6 is connected to the source region and the drain region of the polysilicon semiconductor layer 4 through via holes in the interlayer insulating layer 5 . In all the drawings of the present invention, the positions of the source and the drain can be interchanged.

The preparation method of the flexible backplane includes the following steps:

S21, preparing the gate layer

According to the method of embodiment 1 or embodiment 2, a flexible conductive wire is prepared as a gate layer;

S22, preparing gate insulating layer, polysilicon semiconductor layer and interlayer insulating layer

Depositing a gate insulating layer, a polysilicon semiconductor layer and an interlayer insulating layer on the gate layer prepared in step S21, and etching the interlayer insulating layer to form a contact hole to expose the polysilicon semiconductor layer;

S22, preparing source and drain layers

According to the method of embodiment 1 or embodiment 2, the contact hole formed by etching in the step S22 is used to prepare flexible conductive wires as source and drain electrodes. The glass substrate described in Embodiment 1 or Embodiment 2 is equivalent to the hole wall of the contact hole in this step.

When the flexible substrate prepared in this embodiment is bent, the resistance of the conductive line of the TFT will not increase sharply or break, which increases the reliability of the device.

Application example 2

As shown in Figure 6, a flexible backplane includes a flexible substrate 1 and a top-gate TFT formed on the flexible substrate 1, and the TFT includes an active layer 7 formed on the flexible substrate, a gate insulating Layer 3, interlayer insulating layer 5, gate layer 2 and source/drain electrode layer 6, the gate layer 2 and/or source/drain electrode layer 6 are the flexible conductive wires. As other implementations, the TFT can also be: the gate layer 2 adopts the flexible conductive line structure prepared in Example 1 or Example 2, and the source/drain electrode layer 6 adopts a common existing structure; or the source/drain electrode Layer 6 adopts the flexible conductive wire prepared in embodiment 1 or embodiment 2, and gate layer 2 adopts a common existing structure.

The preparation method of the flexible backplane includes the following steps:

S31, preparing the active layer and the gate insulating layer

Deposit active layer and gate insulating layer on flexible substrate;

S32, preparing the gate layer

According to the method described in Example 1 or Example 2, a flexible conductive wire is prepared on the gate insulating layer as a gate layer; the glass substrate described in Example 1 or Example 2 should be the gate electrode in this step. Insulation;

S33. Preparing an interlayer insulating layer

Depositing an interlayer insulating layer on the basis of the step S32, and etching the interlayer insulating layer and the gate insulating layer to form a contact hole to expose the active layer

S34, preparing source and drain layers

According to the method described in Embodiment 1 or Embodiment 2, the contact hole formed by etching in the step S33 is used to prepare flexible conductive wires as source and drain electrodes. The glass substrate described in Embodiment 1 or Embodiment 2 is equivalent to the hole wall of the contact hole in this step.

When the flexible substrate prepared in this embodiment is bent, the resistance of the conductive line of the TFT will not increase sharply or break, which increases the reliability of the device.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. A preparation method of flexible conductive wire, is characterized in that, comprises the steps: S11: Preparation of microsphere dispersion Add the microspheres into the solvent and disperse evenly to obtain a microsphere dispersion; S12: Preparation of microsphere template array coating the microsphere dispersion on the substrate, drying and removing the solvent to obtain a microsphere template array; S13: depositing metal lines Depositing a metal layer on the microsphere template, the metal layer filled in the surface of the microsphere and the gap between the microspheres forms a metal film with a network structure; S14, forming a flexible conductive wire After removing the substrate and the microspheres, the metal film with a network structure is etched into a flexible conductive line of a predetermined shape. 2. The method for preparing a flexible conductive wire according to claim 1, wherein the step S11 is: Add the microspheres into the water or organic solution, then add the surfactant, and then distribute the microspheres evenly in the solution by ultrasonic vibration to form a microsphere dispersion. 3. The method for preparing the flexible conductive wire according to claim 2, characterized in that the diameter of the microspheres is 12nm-3um. 4. The method for preparing a flexible conductive wire according to any one of claims 1-3, wherein the concentration of the microspheres is 0.01-0.15wt%, and the microspheres are polystyrene microspheres or carbon dioxide Silica microspheres. 5. The method for preparing a flexible conductive wire according to any one of claims 1-3, characterized in that, the step S14 is: Ultrasonic oscillation or high-temperature annealing in the solution removes the microspheres, and then performs vacuum annealing to obtain a metal film with a network structure, and then etches the metal film with a network structure into a flexible conductive wire of a predetermined shape. 6 . The method for preparing a flexible conductive wire according to claim 5 , wherein the metal layer in step S13 is one of copper, aluminum, molybdenum or titanium or a combination of several of them. 7. A flexible conductive wire prepared by the method for preparing the flexible conductive wire according to any one of claims 1-6. 8. A flexible backplane, comprising a flexible substrate and a TFT formed on the flexible substrate, characterized in that the gate layer and/or source/drain electrode layer of the TFT is any one of claims 1-6. The flexible conductive wire described above. 9. A method for preparing a flexible backplane, comprising the following steps: S21, preparing the gate layer According to the method described in any one of claims 1-6, flexible conductive wires are prepared as gate layer; S22, preparing gate insulating layer, polysilicon semiconductor layer and interlayer insulating layer Depositing a gate insulating layer, a polysilicon semiconductor layer and an interlayer insulating layer on the gate layer prepared in step S21, and etching the interlayer insulating layer to form a contact hole to expose the polysilicon semiconductor layer; S22, preparing source and drain layers According to the method of any one of claims 1-6, the contact holes formed by etching in the step S21 are used to prepare flexible conductive lines as source and drain electrodes. 10. A method for preparing a flexible backplane, comprising the following steps: S31, preparing the active layer and the gate insulating layer Deposit active layer and gate insulating layer on flexible substrate; S32, preparing the gate layer preparing a flexible conductive line on the gate insulating layer as a gate layer according to any one of claims 1-6; S33. Preparing an interlayer insulating layer Depositing an interlayer insulating layer on the basis of the step S32, and etching the interlayer insulating layer and the gate insulating layer to form a contact hole to expose the active layer; S34, preparing source and drain layers According to the method according to any one of claims 1-6, the contact holes formed by etching in the step S34 are used to prepare flexible conductive lines as source and drain electrodes.